Modulation of human granulopoiesis by macrophage-derived growth regulators.

The response of granulocyte progenitors (CFU-D) from patients with chronic myeloid leukaemia (CML), neutrophilic reaction (NR) and healthy subjects to macrophage-derived stimulatory and inhibitory factors was investigated in diffusion chamber culture. CFU-D from CML and NR demonstrated a normal reactivity to macrophage stimulation but were hyporesponsive to indomethacin-sensitive inhibition. It is also shown that the spleens of patients with Hodgkin's disease contain locally activated macrophages with higher production of indomethacin-sensitive growth inhibiting factor for autologous CFU-D clonal proliferation.